Bleeding Brakes

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blue_cortina
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Bleeding Brakes

Post by blue_cortina »

Hi Everyone
I've been working on my son's car for the last couple of years and I'm (hopefully) nearly at the stage where it can go back on the road. My current issue is the brakes. I've worked on plenty of other classic cars so I'm not clueless but the system on these cars has caused me many issues.

I'll try and list what has been done first to give you an Idea of the history:
Replaced MC with new lockheed one. Replaced all four front wheel cylinders and both hoses. Replaced rear wheel cylinders, shoes and drums, beehive springs (previously missing), and, copper washers. Car had a servo fitted and that remains but I have rerouted it to work on all four corners - it previously worked only on the fronts. Brake pedal free travel adjusted to 3/4" at pedal. All shoes adjusted right the way up for bleeding (aware it's one click back for normal use).
I've tried eezibleed (made modified cap) and two person bleed.

The issue is I can't seem to get the system to a state where the pedal travel isn't nearly to the floor - ironically that's what it was like before I started. It is firm at the end of travel. How much travel is normal at the pedal after the 3/4" ??

Any further advice on bleeding?? I've read so many posts now that my head is about to go pop... and I'm really hoping to get this car moving again (and be able to stop).

(P.S. One issue I did have was the brand new banjo I fitted had flats that we not parallel so I couldn't stop it leaking - reverted back to the old one, plus reannealed the new washers just in case)
Helping my son with his Morris Minor 1970 Panda Car Replica (both club members)
Myrtles Man
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Re: Bleeding Brakes

Post by Myrtles Man »

You might find some useful pointers in this thread:-

viewtopic.php?t=74182
jaekl
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Re: Bleeding Brakes

Post by jaekl »

Was the engine running to supply vacuum to the server?
blue_cortina
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Re: Bleeding Brakes

Post by blue_cortina »

Thanks for the links - looks interesting reading - I'd not seen those threads on the servo bits.

No - the engine was not running - so no servo effect. This is was neither when bleeding or trying. Starting/running the car is the next issue to sort :wink:

Air valve does not point up.
Helping my son with his Morris Minor 1970 Panda Car Replica (both club members)
blue_cortina
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Re: Bleeding Brakes

Post by blue_cortina »

Still having no luck with the brakes - I'm now suspecting a dodgy servo. It about the only bit I've not had apart. Is there a good way of testing it ?
Helping my son with his Morris Minor 1970 Panda Car Replica (both club members)
ManyMinors
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Re: Bleeding Brakes

Post by ManyMinors »

One of my Minors had been fitted with a servo prior to my ownership. It gave me nothing but trouble, was in the way of other components and didn't perform any useful function so I removed it, threw it away and converted the pipework back to standard. Clearly there was something wrong with the servo or its installation but the brakes were immediately much improved, with a much better feel and the car easier to maintain :D
myoldjalopy
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Re: Bleeding Brakes

Post by myoldjalopy »

I agree - simpler set-ups = less to go wrong and easier to fix if it does!
kevin s
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Re: Bleeding Brakes

Post by kevin s »

Most of the servo's need the cylinder pointing at least slightly upwards to bleed properly, we have a modern one on our minor installed like this and it bleeds fine with a nice firm pedal.

Some of the older ones can be a nightmare, I had a Girling one on my Elan (original fitment) the brake pedal was never very good and despite being rebuilt it would occasionally swallow all the brake fluid.
oliver90owner
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Re: Bleeding Brakes

Post by oliver90owner »

There are what I might call luddites, out there!

Think just a tiny bit (it shouldn’t need to take long): How many cars produced these days use a non-servo braking system. That alone should tell you something.

Back in the late ‘60s, early ‘70s, we made our (mostly) Fords go much faster than the standard models. We fitted servos to improve the brakes (after changing from drums, if fitted). There was no real comparison necessary. They were better, much better.

My 1970 Escort ex-panda car ended up with just the following changed. Headlights (to halogen), engine to 15/1600 GT plus, wheels, tyres, suspension (front and rear), gearbox, differential, diaphragm clutch (to suit the engine power/torque), front seats, steering wheel. About the only thing not up-graded was the rear springs - but only because they were already the heavier-duty, for police use (they were changed, mind - they did break on occasions). As I recall, the front brakes, springs and servo were derived from a crashed V4 Corsair GT.

Respondents, on here, will tell you they can lock their wheels with their drum brakes. That may be the case, but it most certainly is not the way to use your brakes, for stopping from speed. It’s why they now fit ABS as a modern safety addition, isn’t it?
simmitc
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Re: Bleeding Brakes

Post by simmitc »

Although the free play is important to ensure that the ports in the MC are clear, I have seen cases where the yoke needs to be adjusted to reduce pedal travel. It's worth checking the dimensions of the yoke to make sure that it hasn't been shortened. IF the system always works with the pedal near the floor, and does not require pumping, then it might be fully bled, and it's just necessary to get the pedal higher.
ManyMinors
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Re: Bleeding Brakes

Post by ManyMinors »

oliver90owner wrote: Wed Jun 08, 2022 11:01 am There are what I might call luddites, out there!

Think just a tiny bit (it shouldn’t need to take long): How many cars produced these days use a non-servo braking system. That alone should tell you something.
Yes. It tells me that modern cars are unnecessarily complicated and impossible to look after and self-maintain in the long-term. That is why I like to own Morris Minors. My Minor 1000 performs perfectly well, and suits my requirements as an inexpensive, reliable and easy to maintain second car. I have never felt the need to modify it beyond the fitting of flashing indicators and radial ply tyres for my own purposes. I have no problem with other owners wanting to do so but modifications are not needed in order to own and drive a Morris Minor several thousand miles per year and whether a servo really "improves the brakes" is questionable. I have tried one, didn't like it, so removed it but if you're happy with yours, that is fine :)
myoldjalopy
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Re: Bleeding Brakes

Post by myoldjalopy »

if there were any real 'luddites' on here they would be calling for the abolishment of cars altogether! :roll:
blue_cortina
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Re: Bleeding Brakes

Post by blue_cortina »

I was concerned that the very mention of a servo would cause a minor riot, sorry. I've run cars with very simple brake circuits (1964) to those with dual circuit/all-disc/ABS (1996) and can appreciate there is advantages with both.

I'm going to investigate the servo as I don't believe it's doing anything at the moment and could be causing idling issues on the car. Beside it's a classic car so you have to eventually take everything apart.
Helping my son with his Morris Minor 1970 Panda Car Replica (both club members)
blue_cortina
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Re: Bleeding Brakes

Post by blue_cortina »

Since the last post I have taken the servo out of the loop and replumbed the system to work without. When I took apart the servo there was a litre of brake fluid inside oin the air side. Managed to get a really neat video of it all pouring out and me panicking.

Rebled the system and it seemed a little better but not right. I've now put all of the car back together - fist time in over a year it's has wheels. Tried it and still nothing. Pedal still travels an inch and a half after taking up the half-inch freeplay. I've walked away from it for the moment as completely downhearted. Will try again when weather is nice again and I have the chance to spend time on it. To add insult to injury I've now spotted that I dripped brake fluid on the newly painted wing...
Helping my son with his Morris Minor 1970 Panda Car Replica (both club members)
Classiccars
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Re: Bleeding Brakes

Post by Classiccars »

Why do jobs on cars make more jobs.
les
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Re: Bleeding Brakes

Post by les »

Repairing one issue can highlight the problem that caused the original issue, so that in turn needs fixing and so on.

myoldjalopy
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Re: Bleeding Brakes

Post by myoldjalopy »

Or, as you do one job, you notice something else that needs attention - oil leak, bad wiring, rust, missing bolt, perished rubbers etc. etc.
blue_cortina
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Re: Bleeding Brakes

Post by blue_cortina »

Yes classic cars are often aa can of worms. One job leads to another - especially if they have not been maintained to a high standard in the past.

So with the servo taken out of the equation and pipes reconnected accordingly I re-bled the entire system. There seemed to be an improvement but I believe its still not right. After the initial half inch free play there is still inch and half of travel before pedal is firm and that only an inch or so away from the floor. I tried it at low speed and brakes seemed poor, certainly not at road test quality yet. I have walked away from it for a few days and with other things going on it'll probably be next week until I try again.

It's a shame as seeing the car on all four newly revamped wheels and tyres, carpets and seats fitted and all the tools taken out it was looking rather drivable!

So one question for you all - for those with all drums - After the intial half inch free play how much travel do you have at the pedal before its firm ???
Helping my son with his Morris Minor 1970 Panda Car Replica (both club members)
ManyMinors
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Re: Bleeding Brakes

Post by ManyMinors »

I wouldn't worry TOO much about the pedal travel at this stage. I've just read through this thread again and you mention having fitted new shoes front and back I think? That is something I try to avoid for exactly this reason because I have found that the brakes generally have poor feel and long travel for a few hundred miles until the new shoes have bedded in and then been re-adjusted. Some brakes parts are cheap and poor quality too and don't give the best braking but I would say that if you get a firm pedal before the it reaches the floor, then that it a good start and perhaps you should try driving the car a bit and then re-adjusting later after adding some mileage? One more thing you could try...Have you tried clamping off one flexible hose at a time to eliminate that part of the system? That might give an indication of where the most travel is coming from.
Don't give up. Keep persevering and you'll get there in the end :wink:
Myrtles Man
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Re: Bleeding Brakes

Post by Myrtles Man »

blue_cortina wrote: Wed Jul 06, 2022 12:10 pm After the initial half inch free play there is still inch and half of travel before pedal is firm and that only an inch or so away from the floor. I tried it at low speed and brakes seemed poor, certainly not at road test quality yet.


Have you tried pumping the brake pedal and if so, does the firmness come back up the pedal's travel?
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